we continue to look through the charges against dzhokhar tsarnaev. we'll bring you the latest developments. also renewed calls today by law enforcement for more surveillance cameras in our towns and cities. officials say the boston investigation is proof that security cameras can play a key role in catching suspects. >> i am a major proponent of cameras. more cameras the better. i think the privacy issue has been taken off the table. >> listen to these numbers. according to a market research group, an estimated 30 million surveillance cameras have been sold in the u.s. since 9/11. there are 3,000 surveillance cameras in new york's financial district alone. a security network known as the so-called ring of steel. philadelphia police commissioner charles ramsey said he would like to welcome a similar system in his city. >> i wish we had the 3,000 cameras, to be honest with you. listen, it is an invaluable investigative tool. >> our next guest says the privacy concerns are real. that continue creased surveillance should, quote, give us pause. neil richa